A climate control unit is a laboratory apparatus for the storage of predominantly biological or chemical specimens in definite climatic conditions. Examples of this are incubators and cooling or freezing units. Such climate control units have a storage section that is enclosed by a housing making it gastight and thermally isolated. The storage section is accessible via an opening that frequently takes up the entire front side of the climate control unit and that can be closed with a closing device so that it is gastight. Usually the storage section is provided with horizontal inserts for storing the specimens. Climate control units of such type offer in their storage section a climate with predetermined temperature and air moisture and also a predetermined CO.sub.2 concentration in the case of incubators. The closing device is often an external swing door behind which usually a transparent inner door is arranged as a gas screen. This transparent inner door prevents a fast gas exchange from taking place between the storage section and the surroundings when the external swing door is opened. At the same time the transparent gas screen allows the view of the samples. So opening times of the gas screen can be reduced to a minimum, thus largely avoiding unnecessary disturbances in the storage section climate. In order to further reduce disturbances, divided enclosures and partitioned gas screens are known. For example, there are gas screens with six separate access openings each of which is closable by its own door. Such partitioned gas screens make it possible to access definite enclosures and storage cells whereby the other storage cells stay protected.
A prevalent method for the humidification of the atmosphere of an incubator takes place via passive evaporation of water in an open water bath (water bath). While the advantage is a very homogenous distribution of moisture in the air, the disadvantage is the open water surface. Dirt particles, viruses, fungi, bacteria and mycoplasma grow in the water bath in great quantity once they have entered into the water through drops or dust.
A risk of contamination exists for the specimens also through other specimens. On the one hand the specimens can be infested with foreign germs such as fungi or bacteria. On the other hand even the specimens themselves can be dangerous agents. This can mean a risk for other specimens through cross-contamination and also for the operating person. If the storage section of the climate control unit is contaminated, mostly an expensive disinfection of the entire equipment is required resulting in long down times.
For the prevention of contamination and cross-contamination membrane pouches made out of germ-proof membrane are known. Individual specimen carriers can be packed and sealed in such membrane pouches and stored in a climate control unit. However the handling of these membrane pouches is considered to be inconvenient. Accordingly they find a low level of acceptance among users.
With this background the task underlying the present invention is to specify a climate control unit that reduces the risk of contamination of the entire equipment and of cross-contamination and is user-friendly in spite of that.